Table 7.
Definition, relevant exposure period, and additional eligibility criteria for each outcome measure
| Cohort | Outcome | Outcome definition | Outcome-specific exposure period (for infection or vaccination) | Additional eligibility criteriaa |
|---|---|---|---|---|
| 1 | Stillbirth | Spontaneous foetal loss at ≥20 + 0 gestation from any cause | From 6 weeks preconception to end of pregnancy | No additional criteria |
| 1 | Extended perinatal mortality | Stillbirth or neonatal death from any cause | From 6 weeks preconception to end of pregnancy | No additional criteria |
| 2 | Neonatal mortality | Death of live born neonate within 28 days of birth from any cause | From 6 weeks preconception to end of pregnancy | Live births only |
| 3 | Small-for-gestational age | Birthweight <10th centile by WHO-UK90 growth reference | From 6 weeks preconception to end of pregnancy | Live births from 23 + 0 to 42 + 6 gestation only |
| 3 | Very small-for-gestational age | Birthweight <3rd centile by WHO-UK90 growth reference | From 6 weeks preconception to end of pregnancy | Live births from 23 + 0 to 42 + 6 gestation only |
| 4 | Low Apgar score | 5 min Apgar score <7 | From 6 weeks preconception to end of pregnancy | Live births at ≥37 + 0 gestation only |
| 4 | Very low Apgar score | 5 min Apgar score <4 | From 6 weeks preconception to end of pregnancy | Live births at ≥37 + 0 gestation only |
| 5 | Preterm birth | Births <37 + 0 gestation | From 6 weeks preconception to 36 + 6 gestation | Live births only |
| 5 | Spontaneous preterm birth | Births <37 + 0 gestation following P-PROM or spontaneous onset of labour reported on delivery records | From 6 weeks preconception to 36 + 6 gestation | Live births only |
| 5 | Provider-initiated preterm birth | Births <37 + 0 gestation following induction of labour or pre-labour caesarean section reported on delivery records or, in the absence of these data, where delivery occurred during a critical care admission | From 6 weeks preconception to 36 + 6 gestation | Live births only |
| 6 | Very preterm birth | Births <32 + 0 gestation | From 6 weeks preconception to 31 + 6 weeks gestation | Live births only |
| 6 | Spontaneous very preterm birth | Births <32 + 0 gestation following P-PROM or spontaneous onset of labour reported on delivery records | From 6 weeks preconception to 31 + 6 weeks gestation | Live births only |
| 6 | Provider-initiated very preterm birth | Births <32 + 0 gestation following induction of labour or pre-labour caesarean section reported on delivery records or, in the absence of these data, where delivery occurred during a critical care admission | From 6 weeks preconception to 31 + 6 weeks gestation | Live births only |
| 7 | Maternal critical care admission and/or death | Critical (intensive or high dependency) care admission as identified on SICSAG record or death from any cause following exposure/matching during pregnancy and within 42 days of the end of pregnancy as identified in NRS death records | From 6 weeks preconception to end of pregnancy | No additional criteria |
| 8 | Maternal venous thromboembolism | Venous thromboembolism recorded on general acute, maternity, or critical care discharge record during pregnancy or within 42 days of the end of pregnancyb | From 6 weeks preconception to end of pregnancy | Excluding any pregnancies with venous thromboembolism before exposure |
| 9 | Maternal hypertensive disorders of pregnancy | Hypertensive disorder of pregnancy recorded on general acute, maternity, or critical care discharge record during pregnancy or within 42 days of the end of pregnancyb | From 6 weeks preconception to end of pregnancy | Excluding any pregnancies with hypertensive disorders of pregnancy before exposure |
| 10 | Maternal pregnancy-related bleeding | Pregnancy-related bleeding recorded on general acute, maternity, or critical care discharge record during pregnancy or within 42 days of the end of pregnancyb | From 6 weeks preconception to end of pregnancy | Excluding any pregnancies with pregnancy-related bleeding before exposure |
aBeyond core study inclusion criteria (singleton pregnancies ending in live or stillbirth at ≥20 + 0 gestation from relevant date range).
bSee Supplementary Table 10 for the diagnostic codes indicating these outcomes.
P-PROM Preterm Premature Rupture Of Membranes; SICSAG Scottish Intensive Care Society Audit Group.